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Raspberry Pi

Tuesday 22nd May, 2012

No review is ever written in isolation, absent from context. Usually, you can guess the reviewer’s bias within a few paragraphs, and compensate accordingly. He hates LCD display quality, she dislikes proprietary software, they yearn for the days of full bandwidth vinyl. You get the idea.

So here’s some context up front. This July, I’ll have been writing hardware and software reviews for 22 years and, for me, reviewing the Raspberry Pi (R≈ì√Ñ) is a first on two counts: one, I’ve never had to review what amounts to a physical manifesto before, and two, as a 43-year-old father of two wee boys - squarely pegged in the reliving-my-youth demographic - I so so so want this pocket-money PC to succeed. But understand, this is neither pure nostalgia, nor am I alone. The stated aim of the Raspberry Pi Foundation is to provide a modern, inexpensive counterpart to “the Amigas, BBC Micros, Spectrum ZX and Commodore 64 machines that people of an earlier generation learned to program on.”

As if you were in any doubt, even the naming of the R≈ì√Ñ itself tips the hat to the stalwart of that bygone era: Model A (one USB port, no Ethernet) and Model B (two USB ports, 10/100MBps Ethernet). So what do you get for your money? The R≈ì√Ñ is a credit-card sized GNU/Linux computer with RCA video out, 3.5mm audio out, the appropriate aforementioned USB/Ethernet setup, HDMI out, and an SD card reader for OS and userfile storage. The SD is of course down to cost, but it’s worth pointing out that using an SD for the OS offers a number of benefits; replacement media is relatively cheap; it’s pretty difficult to brick an R≈ì√Ñ in software; image restore is just another SD card away; and pupils can take their drives home with them.

And whilst the R≈ì√Ñ does need to boot from an SD card, it’s possible from the command line to switch post-boot so that the OS and filesystem run from an external USB drive. Additionally, despite no software support as yet, there’s a DSI connector for hooking it up to LCD panels, and the Model B has a [CSI MIPI connector] for adding a camera down the line. There are also GPIO pinouts (though limited to 16 mA according to spec), which could make expansion and hobbyist extras a distinct possibility; projects to tie Arduinos into an R≈ì√Ñ, or use Arduino shields on an R≈ì√Ñ are already off the drawing board. In terms of processor specs, the R≈ì√Ñ is built around a Broadcom BCM2835 32-bit system-on-chip clocked at 700MHz, a VideoCore IV GPU running at 250MHz - hence the 1080p full HD support - and 256MB of LPDDR memory shared between them.

HD ready

The RAM split is determined at startup with an appropriate armX_start.elf file, so for different splits you need to reboot the R≈ì√Ñ. For those into their bare metal, there’s also a config.txt file that allows you adjust the settings to overclock the CPU, GPU, and memory. Some brave souls out there are claiming to run it at over 900MHz, but we only have the one board to test, so good luck with that… The R≈ì√Ñ ships as just a circuit board, although the proposed Autumn Educational release promises a case for the same money. But either way, you’ll still need to cough up for a list of peripherals. How much extra are you going to need to spend? At a minimum you’re looking at a mouse, keyboard, HDMI cable or RF cable, a power supply, and an SD card. The supply is from a USB cable, so you need a decent powered hub, or USB charging socket. In testing I found that an iPhone or even a Kindle charger did a fine job, and once I could prise my kiddiewinks away from CBBC, the 22in family LCD telly was perfectly adequate.

Admittedly for most households these days it should be a 5-minute job to scrounge up what’s needed, and it may seem nit-picking to go on about the cost of peripherals. But given that the most important fact about the R≈ì√Ñ is that it’s priced at $25. OK, so in UK it’ll be nearer £29 with delivery and VAT, but who’s counting? Still, it’s instructive to realise that the board itself may cost less than splashing out on the power supply & cabling. And yes, sorry, must stop calling it a board; it really is a PC. Indeed the R≈ì√Ñ Foundation could rightfully claim the title of cheapest bare-bones PC on the market. There are other contenders that can at least see the ballpark, but none actually within reach of the target markets' spending limit. Or as it’s more commonly known, pocket money. Once you have it up and running, and plugged into your display of choice, it’s time to start running through the demos on the Demo SD card. The card we were shipped came with Debian Squeeze with an LXDE topping, featuring desktop scripted links to basic apps (AbiWord), programming environments (python games, turtle and Scratch), media box tools (XBMC), graphics demos in Qt, and games (Quake III).

Depending on what you’re looking to do in a particular session you may need to restart the R≈ì√Ñ with a different memory split; the scripts handle it for you. And the demos are pretty good. Given the right box, appropriate external storage, and suitably encoded files, XBMC running on an R≈ì√Ñ would give an AppleTV a run for its money. The Qt graphics demos are fun in a visualiser sort of way, and Quake III… well if I hadn’t had two under-tens hanging over my shoulder at the time I probably would have spent a good hour or two improving my frag stats. At $25 (or £29) the R≈ì√Ñ is an absolutely astounding piece of kit; at delivering content and games. Graphics-wise, it supports h.264 and OpenGL ES 2.0, and is on a par with the original X-Box, with various claimants putting it more 300 per cent ahead of an iPhone 4 in terms of raw power.

In day-to-day use though, is it a PC replacement? Nope, probably not. The main killer is more the 256MB limit, than the clockspeed. It’s fine for word-processing, and a little spreadsheet-ing, but as a thin client, it struggled to deal with the bulk of modern web-app sites - webmail, Dropbox, Stackoverflow and the like - and was prone to hanging when switching between browser windows. This may be down to the current lack of hardware graphics acceleration - which may be addressed in due course. Lest we forget that price is not the only benefit that the R≈ì√Ñ brings: there’s the open source software. Yes it’s a double-edged benefit - some may see an unfamiliar interface and linux-bigotry, but for the target market, education, it’s clearly a win on a number of counts. The software is free, there’s an existing community, and more stuff will get ported to it over time - rumours about Oracle porting a JAVA VM persist, and there’s already ARM versions of Flash out there.

If Debian and LXDE aren’t your cup of tea, other flavours of Linux are available, and if being tarred with the Linux brush is a step too far, other OSes may be in the pipeline. RISC OS, which has a strong following in education, has already been seen in the wild. The price will get it in the doors of schools, and its open source nature will ensure that there’ll be a ready supply of developer tools. More to the point, if it is taken up by education, then it’s unlikely to be as a glorified typewriter. ICT will certainly have to change tack slightly, when the kit they’re given won’t run Office 2010. This may seem a big ‘if’, but with 75,000 registered interests on the RS site by 29th Feb, I’ll take some of that action. The whole point of this adventure is to make something that kids can learn how to program with. As it stands right now, the R≈ì√Ñ has the potential to fulfil its promise: but it’s clearly not there yet. Just having the kit out there is not enough.

To paraphrase one astute El Reg commentard, “it’s the manuals stupid”. To its great credit, the Raspberry Pi Foundation acknowledges this: an educational release is due in the Autumn, which is expected to include a user guide and programming manual. The R≈ì√Ñ Foundation has said that by default, Python will be the educational language - although anything that will compile for ARM6 is fair game - and a number of well-resourced initiatives are organising materials to exploit the availability of R≈ì√Ñ come the Autumn. But for a grassroots take-up, R≈ì√Ñ will also need tools that make writing teachers' own materials straight forward, and an interface that makes getting started seem less of an initiation into some Linux cult, and more like the “just one way in, zero-distractions, would you like to play a game of chess” command prompt of the the early 80’s.

Verdict

So, tongue slightly in cheek, the ultimate success test for R≈ì√Ñ will be, does it help to initiate a second golden age - or is that Diamond Age - of self-educated programmers? No, this isn’t nostalgia. It’s a reboot; with better production values, a ready-made audience, and priced perfectly for austerity Britain. All we need are some decent writers. Anyone know if Russell T. can write Python? Does anyone have Moffat’s number?